car stereo install and now humming plz help!

[NiSmO_zt]

ok ,so i just bought my second 91 240 se on saturday, and was putting my alpine stereo in it that i know is good, i hooked up the speakers, and the +12 volt solid, and switched, when i turn the key to first notch(accessory), the speakers kind of thump(pfffft), and then the cd player starts, and music plays, fine. when i turn the car on, immediately, a humming noise with a pulsing whir comes over the speakers, with the music still playing fine. when revving it up, the pulsing seems to stay with the rpm, going faster with higher revs, very annoying. any suggestions? the previous owner had some sort of stereo in the car, i found one wire under the dash just wire nutted off. any common causes for this kind of behavior?

oh, and also, a few times, the music would play fine when in accessory mode, but when i turned the car on, the cd player would act like it was playing, counting seconds, but no sound at all would come out, and the buzzing was not there either...

any help is appreciated
thanks
cj

[k3smostwanted]

the cd player needs a ground or better ground. the humming noise is your alternator coming through your speakers caused by the stereo not being ground well enough. the internal amplifer on the cd player is amplifying the noise through your speakers.

take your ground wire coming out of the CD player and connect to something solid metal...like between a bolt and metal or something. that should take care of it...

[AWDSR20]

Right on man! yep thats ur answer buddy! could not explain it better.

BTW its not that hard, fine a better spot and drill it in!

[NiSmO_zt]

thx guys
lata

[musicsurfman]

Actually It Could Possibly Happen By Having A Amp Power Wire Too Close To A Speaker Or The Stereo Unit Power Running Along With The Speaker Wires.

Speaker Wires Should Always Be Isolated From All Power Sources As Interference Like You Are Hearing Happens.

[CA20Guy]

Originally Posted by musicsurfman

Actually It Could Possibly Happen By Having A Amp Power Wire Too Close To A Speaker Or The Stereo Unit Power Running Along With The Speaker Wires.

Speaker Wires Should Always Be Isolated From All Power Sources As Interference Like You Are Hearing Happens.

Hi am new to these forums, but would agree, sounds like "engine noise" .

[AWDSR20]

that was funny LOL
"hi i'm new but yeah i agree" LOL
welcome dude!

[k3smostwanted]

Originally Posted by musicsurfman

Actually It Could Possibly Happen By Having A Amp Power Wire Too Close To A Speaker Or The Stereo Unit Power Running Along With The Speaker Wires.

Speaker Wires Should Always Be Isolated From All Power Sources As Interference Like You Are Hearing Happens.

yeah it could be, but it is just a cd player he said and the speakers should be in the stock location. but yeah, that will cause the alternator noise.

[musicsurfman]

Ohh I Know I Was Just Giving Him More Possibilities, Just In Case He Forgot To List Something Or He Made Changes To The Stock Setup.

[NiSmO_zt]

naw, the speakers are all in stock locations, but the previous owner had a changer or a sub or something, cause i found an aux wire running to the back of the car, and i had to match the factory wires up to the alpines harness wires, cause he lopped off the factory plug bit.